x/pkgsite: builtins with lowercase names not searchable

[seebs]

What is the URL of the page with the issue?

https://pkg.go.dev/search?q=builtin.make&m=symbol

What is your user agent?

firefox

Screenshot

sorry, don't have one handy

What did you do?

search for make on pkg.go.dev

What did you see happen?

results for Make

What did you expect to see?

builtin.make, aka the make function that's part of the base language.

it looks to me like pkg.go.dev is (correctly for EVERY OTHER case) only searching for exported symbols, but for the handful of language builtins (make, min, max, nil, etc) with lowercase names that are predeclared identifiers, this isn't working.